The invention concerns a valve connector for connecting to inflation valves of vehicle tires.
For reasons of clarity, some of the standards used will be cited. In the ISO standard No. 10475:1992(E), thread for tire inflation valves of vehicles is described. The most used threads are designated 5V2 (DIN: Vg 5,2), which has a nominal diameter of 5.2 mm and a pitch of 1.058 mm, and 8V1 (DIN: Vg 8), that has a nominal diameter of 7.7 mm and a pitch of 0.794 mm respectively. These thread types are used in the valve types of Dunlop-Woods, Sclaverand or Schrader. The last mentioned valve type is frequently used on common cars, where a spring-loaded core pin in the valve must be kept down in preparation of the passage of air, while pumping a tire. For this purpose, the valve connector must be equipped with suitable means, which can serve this aim. Moreover, suitable means, e.g., a contra valve or the like, must be used to ensure that loss of air is avoided when activating the valve plug pin. The Sclaverand valvexe2x80x94just like the Dunlop-Woods valvexe2x80x94the distinctive character that its plug pin is solely opened by air pressure. The necessary air pressure for opening a Sclaverand valve is up to 16 bar, and the valve is mostly used in connection with high-pressure tires with a pressure of up to 16 bar. The opening pressure for the Dunlop-Woods valve is approximately 4 bar, which ensures that it is easier to open.
Well-known valve connectors (e.g., GB-B-977,139) can only be connected to the Dunlop Woods valve type and/or the Sclaverand valve type, or the Schrader valve type.
A well-known connector for a Schrader valve is of the type, where a rubber cylinder is tightly squeezed against the stem by means of a lever, which axially compresses the rubber cylinder. Consequently, the rubber cylinder is squeezed radially against the stem. With reference to different valve diameters, it is necessary, that auxiliary equipment, such as nut 6, is screwed onto or out of the valve thread to reduce or increase the internal diameter in advance to ensure the establishment of a connection from the valve connector to other valve diameters. Loose parts can disappear and can be loosened when used, if the pump hose is turned, so that the connection is no longer air-tight.
GB-A-15 99 304 shows a universal valve connector which can be screwed on all valve types. The thread (4) corresponding to 8V1 also keeps the bushing (26) in position. The bushing (26) an internal thread (30) corresponding to 5V2 for Sclaverand or Dunlop-Woods valves. The plug pin of the Schrader valve is opened mechanically by means of a stationary pin indicated with (12). The disadvantage of this connector type is that the bushing (26) with a 5V2 thread has to be removed before connecting to a Schrader valve, and also that the bushing (26) must be mounted again before connecting to a Dunlop-Woods or Sclaverand valve. Also in this case loose parts are used. They can disappear and loosen when used, if the pump hose is turned, resulting in an untight connection.
From DE-A-38 19 771, a universal connector on a handpump with two coupling holes is known[: one] for Dunlop-Woods and Sclaverand valves and one for Schrader valves of which the plug pin is opened mechanically. The disadvantage of this way of coupling is firstly, that it cannot be fastened to a valve and secondly, that, it can, only be used in a certain position, where the coupling hole is turned almost vertically upwards, and finally that the user to find out which of the two holes to use for the valve in question.
From WO-A-92/22448, it is known to provide a sealing means, which is placed in a single level, from GB-B-977.139 a valve connector operated by a lever cam is known. Common to both prior art references is that they can only be used together with a Schrader valve, and that neither Sclaverand type nor Dunlop-Woods type valves can be served by this type of connector, as the sealing means only show one diameter fitting e.g., the Schrader valve.
Inflating a tire is a problem too many people, especially if the tires have different valve types, and only one pump to be used. This is the case in most households. The aim of the invention is to provide a valve connector which fits on all current valve types, which is easy to operate, is economical, and which has the possibility of automatically adjusts itself to the valve in question. Also, it should be possible to use the connector with existing pumps.
According to the invention this task is solved by means of the provisions in claim 1.
By a connector for inflation valves of vehicle tires, where the connector consists of a housing connected to a pressure source, preferably a hand or foot pump, and with a coupling hole with a diameter corresponding to the diameter of the valve to which it is connected, where the coupling hole is equipped with a securing means for securing on the valve and a sealing means against valves of different sizes, the sealing means is mounted coaxially in the connector housing and is established on at least two parallel separate levels having the centre line of the connector housing, which is coaxial to the centre line of the valve when used, as is normal, where the internal diameter of the sealing means approximately corresponds to the external diameter of the present valve dimensions, on which the connector is mounted when used. The sealing means which is nearest to the opening of the coupling hole in the connector housing has the biggest diameter, while the sealing means which is farthest from the opening of the coupling hole in the connector housing has the smallest diameter, and diameters between the extremes are lying in corresponding separate distances between these extremes. The coupling place on a valve, which is to be connected, is positioned against a sealing surface on the sealing means in the coupling hole of the concerned valve. The connector has only one coupling hole. The use of it is therefore simple, even without a user manual, and loose nipples are superfluous. Therefore, a connection can always be established in only one operation.
The securing means is a rotational bushing mounted on the housing, which is equipped with a thread in the coupling hole, which fits on the respective valves, and which is sealed with the sealing means against the connector housing, which is farthest from the coupling hole in the connector housing. The connector can be positioned here on the valve with an airtight connection, which does not become untight, when the connected hose is turned. In addition, mounting is quickly accomplished without applying significant strength. (Dis)-Connecting of the coupling can be done using only one hand.
To reduce the wear of the gasket seal surface in the connector housing and also to reduce the force by means of which the rotational bushing has to be turned, and furthermore to ensure a reliable sealing against valves with 5V2 thread, the innermost thread may be provided by a bushing with a 5V2 thread, where the bushing is embedded and slightly axially sliding in a taper milling in the rotational coupling bushing and is coupled rotational-free to the coupling bushing by means of a set of ribs, which are distributed around the bushing circumference, and which are geared into corresponding grooves in the coupling bushing, wherein the sealing means rests on a stepped milling. This ensures that frictional forces do not occur between the gasket seal and the coupling bushing during the main part of its fastening and unscrewing, whereas the coupling bushing is pulling the connector housing and its gasket seal against the valve when tightening. Tightening occurs against the core of the valve thread and is stabilized as a result of the reduced radius of the inner part of the gasket seal.
In order to be able to use the valve connector on a Sclaverand type valve, which is not standardized, i.e., some of the threads are removed thereby forming two parallel secants on each side of the Sclaverand type valve, a further development of the inner bushing is suggested, whereby the inner bushing is running in an undercut groove in the valve housing. Such Sclaverand type valve cannot tighten against the sealing means, and the pressurized air will try to escape through the secant openings. By running in the undercut groove the bushing will tighten against this when mounting the valve connector on the valve.
In connection with the (dis)connection with only one hand, almost the same is valid, if the connector is provided by means of temporary thread, i.e., created by squeezing e.g., a rubber cylinder against the existing valve thread of which the securing means and sealing means in a well-known way consist of the bushing of a deformable material positioned in the housing, preferably a rubber type material shaped like a xe2x80x9cHxe2x80x9d, and that a piston is mounted proximally to the valve and the rubber bushing which has two extremes to establish an axial compression and release of the rubber bushing, and also a lever for activating the piston, where the axis of the lever is placed perpendicularly to the centre line and eccentric with this, and that the lever for activating the piston is turned from a position forming an angle "psgr" with the centre line to a position almost perpendicular to the centre line, where a locking means of the lever is working together with a corresponding locking means of the housing, whereby the locking means of the lever, as an example, is provided in the construction of the lever. In a special advantageous embodiment a reaction arm is applied to absorb the reaction forces originating from the movement of the lever arm between the two positions. This measure ensures a reliable securing and a simple operation.
With this embodiment of the connector, it is possible to mount same, using just one hand, as the lever is taken down to its locking position by just a simple squeezing of the lever and the reaction arm parallel to the hose connection on the connector housing. By this action the piston is pressed against the rubber bushing, which is tightly squeezed radially against the concerned valve.
In an improved embodiment of the valve connector, the rubber bushing is provided with at the least one external V-shaped incision in the circumference perpendicular to the center axis close to those parts squeezing against the threads of the valve. Through such incisions the rubber bushing is predetermined to exert the largest radial force against the threads exactly where the incisions are, and the user of the valve connector will experience a soft working lever arm. In order to support this purpose further and securing the valve connector on the valve even under high pressures it is suggested, that a preferably toroidal shaped ring is arranged in the incisions, thereby stressing the exerted radial forces.
The embodiment with the lever arm is designated: a torque-free (dis)-connection, as the valve may not carry any torque by the (dis)-connection. Connection to almost all valves is possible, as such connectorxe2x80x94type might be able to open a plug pin in such Schrader valve, which is opening at an air pressure of approximately 5-6 bar. The air pressure in the pump hose is of the same magnitude as when a high-pressure tire provided with a Sclaverand valve is inflated. This is optimally achieved by using a high-pressure hand or foot-operated bicycle pump. There are plug pin types which cannot be opened by means of air pressure of an ordinary bicycle pump (e.g., 10 bar max.). Connecting can be done easily and comfortably in two ways. Either the last mentioned plug type is being replaced with the first mentioned one and the embodiments of the invention without a pin are being used as a connector, or the plug can, according to an appropriate embodiment of the invention, be opened by a pin placed in continuation of and coaxially to the centre line of the connector housing, which is transported by axial shifting from a position farthest from, the valve (FIG. 4A) to activate the central pin head of the plug (FIG. 4B). By this embodiment, the necessary pumping force is considerably lower, when a Schrader valve is to be inflated, because no air pressure is used for opening the valve. Inflation can therefore be done with an ordinary bicycle pump.
As a means for automatic sliding the activating pin in the housing from a passive to an active position, the activating pin is constructed as a piston equipped with a suitable securing means arid a piston rod, which can slide in the cylinder shaped housing, and which, without any physical load, is held in a sealing longitudinal position against the cylinder wall, so that the sliding of the piston after the connection of the valve connector occurs by means of the compressed air which is transported from the pressure source, and so that the piston in the position farthest from the wheel valve seals less than 100% against the cylinder wall.
With a valve connector according to claim 1 equipped with such automatic sliding activating pin it is possible to mount the valve connector equipped with a valve to a compressor hose, which can be available to the public known, e.g., from bicycle shops, etc. Thus, it is not necessary to fasten the valve connector to the valve, as the user exerts the pressure necessary to secure an airtight connection.
With such valve connector, inflating tires without the user having to identify the valve type and functioning has become possible. The operation conveniency has also increased significantly, and it will now be easier for the user to inflate the tire to the correct pressure, which in general eases the driving and reduces tire abrasion. At the same time, a contra valve function is added to the Schrader valves in that the valve only opens the core of the Schrader valve when sufficient air pressure is fed from the pressure source and air thus cannot escape from the tire during inflation.
In an appropriate embodiment of the valve connector according to the invention, it is suggested that the piston is constructed with a central, axially sliding valve, which is elastically pressed to a closing position against the piston top. This provides a well-defined opening zone, which is not influenced by abrasion in the piston guide, and the increasing opening of the core secures the passage of compressed air from the pressure source as well.
As an example, the central, axially sliding valve on the piston can in a suitable way be activated by the fact that the piston valve is levered with a valve lever, which reaches eccentrically through the piston, and by the fact that a spring between the piston and its valve keeps the valve closed when the piston does not influence the core in the wheel valve.
Alternatively, the piston valve can be levered with a core pin, which concentrically reaches axially through the piston, where a spring leads it to a position distally from the piston. It has thus become possible to provide the piston with a reliable function within the limits established by the ISO standard, as the piston with the core pin automatically adjusts its length to the limits of the valve in question.
The latter embodiments ensure a safe functioning of the valve lever, because it is enclosed and only influenced by axially directed forces. Also, the bridge on the Schrader valve can, be used for activating the piston valve. Further, the reaction forces from the piston is led to the air and not to the mechanical constructions.
The Schrader valve has the biggest major diameter of the external thread (thread type ISO 4570/3 8V1, ISO 10475:1992=12V1 resp.) and the coupling place is closest to the opening of the coupling hole. The Dunlop-Woods plugs and the Sclaverand valves have the same thread type, where the major diameter of the external thread (thread type ISO 4570/2 5V2) is smaller than the minor diameter of internal thread 8V1. Therefore, it is possible that the Dunlop-Woods plug type and the Sclaverand valve type can pass both the coupling place of 8V1 threads and 12V1 threads. Consequently, the coupling place of the connecting of 5V2 thread is farthest from the opening of the coupling hole. The 5V2 thread of the Dunlop-Woods plug (both the type which is DIN normed and the type which in daily language is called, the xe2x80x98ball valvexe2x80x99), is sufficiently sticking out over the nut 8V1 which is keeping the plug to the stem and of which the major diameter is less than the minor diameter of the internal thread for the 12V1 thread in the bushing. There is, therefore, enough space for at least two thread types each with a corresponding seal ring. The same applies for the squeezing connections where the connector is squeezed to form a temporary thread. The said 8V1 nut cannot pass the coupling place of the Schrader valve. That is due to the fact that the major diameter of the said nut is bigger than the diameter of the biggest hole in the rubber cylinder (a major diameter of external thread 8V1). The beginning of the coupling place of the 5V2 thread is at distance a from the opening of the coupling hole. As the load on the connection is low, it is not necessary to use the entire length of the internal thread, as generally accepted rules say 0.8xc3x97 of the size of the coupled external thread. This rule is based on mechanical constructions which are high-loaded and where the thread is fastened by a wrench. It is therefore possible that the coupling place of the 5V2 thread is behind the coupling place of the 8V1 thread.
The invention can exist in a number of embodiments that will appear from the dependent claims.